http: fix to use string.IsNullOrWhiteSpace

Co-authored-by: Matthew John Cheetham <[email protected]>

Author: miya789

src/shared/Core/CurlCookie.cs

@@ -38,7 +38,7 @@ public IList<Cookie> Parse(string content)
                     {
                         domain = domain.TrimStart('.');
                     }
-                    var path = parts[2] == "" ? "/" : parts[2];
+                    var path = string.IsNullOrWhiteSpace(parts[2]) ? "/" : parts[2];
                     var secureOnly = parts[3].Equals("TRUE", StringComparison.OrdinalIgnoreCase);
                     var expires = ParseExpires(parts[4]);
                     var name = parts[5];